Troubleshooting motor bearing wear

Rotating equipment such as electrical motors, rotary pumps and compressors as well as fans and blowers, are generally designed for smooth operation – with zero vibration as the idea state.

In this equipment a failed bearing has increased drag, emits more heat, and has lower efficiency because of a mechanical, lubrication, or a wear problem.

Bearing failure can be caused by several factors:

A heavier load than designed for

Inadequate or incorrect lubrication

Ineffective bearing sealing

Shaft misalignment

Incorrect fit

Normal wear

Induced shaft voltages

Before bearings fail, however, the problem is likely to show itself by a telltale vibration. For example, when a roller bearing race becomes pitted, the bearing rollers will cause a vibration each time they pass over the damaged area.

Once bearing failure begins, it also creates a cascade effect that accelerates motor failure. 13 % of motor failures are caused by bearing failure, and more than 60 % of the mechanical failures in a facility are caused by bearing wear, so learning how to troubleshoot this potential problem is an important component of any maintenance program.

A test and measurement instrument such as the Fluke 810 Vibration Tester is designed specifically for maintenance professionals to troubleshoot mechanical problems, including identifying wear to ball or roller bearings.